solution_walkthrough.md

Solution Walkthrough

This document explains how the correct answer can be discovered. Only read on if you want to spoil the surprise..

Read the Crime Scene Report:

bazel build crime_scene_reports:missing_basil_089324

***************
Confidential
***************

The basil was first discovered missing on 28th June 2022.
Two witnesses have came forward with relevant information.

Their names are Amy and Mark. Both witnesses have been interviewed.

This will tell you that there are 2 witnesses. Their names are Amy & Mark.

Crime scene reports are build targets (output isn't repeated if already cached). If you want to see the output again you'll need to run bazel clean first.

List all people

bazel query people/...
//people:amy
//people:basil
//people:john
//people:katie
//people:mark

Find out what targets depend on the two witnesses (Amy & Mark):

bazel query 'rdeps(//..., (//people:mark union //people:amy))'
//interviews:454235
//interviews:565673

This tells us that there were two interviews and gives us the targets for these interviews.

Learn about the interviews:

bazel run //interviews:454235

I saw someone getting into a red car with some basil and they drove away without paying for it.

bazel run //interviews:565673

I saw a tall person running quickly to their car with some basil.

This tells us that the culprit was a tall person with a red car.

Query for all of the red cars:

bazel query 'attr(tags, "red", //cars/...)'
//cars:23245
//cars:85465

This tells us that there are two red cars.

Query to see who depends on the first red car:

bazel query 'rdeps(//..., //cars:23245)'
...
//people:basil

This tells us that a person called Basil owns the first red car.

Query to see who depends on the second red car:

bazel query 'rdeps(//..., //cars:85465)'
...
//people:katie

This tells us that a person called Katie owns the second red car.

Query to see whether Basil or Katie are tall

bazel query 'attr(tags, "tall", (//people:basil union //people:katie))'
//people:basil

This tells that Basil is tall. We already know that he has a red car.

Check if Basil is the correct answer.

bazel test solution --test_env guess=basil
...
//solution:solution  PASSED in 0.1s

The mystery of the stolen basil has been solved! It was Basil.